With the advances of technology, the electronic products are developed in response to the trend of lightness and miniaturization, so as to allow people to be able to use miniaturized electronic products anywhere and at any time. As a type of audio output device, earphones are widely used in the daily lives of people, and have become a necessary device to accompany various types of audio output equipment (for electronic equipment such as CD, MP3, MP4 or computers). The current earphones mainly include two modes; the headwear type earphone and the in-ear type earphone, and the headwear earphone has become widely popular with many consumers due to advantages such as being comfortable to wear and has good audio quality.
Currently, the headwear earphones sold on the market include ear covers on the left and on the right, which are used to provide for the function of sound playback when it is worn on the head of a user; however, this singular function can no longer satisfy the requirements of the consumers.